In my many searches on the net for what helps with glucose, I ran on to a reference (more than one, actually) that says berberine may help. I tried it, and it knocked my glucose down by about 20 points. The dosage will vary according to your weight and degree of insulin resistance, so work with your doctor to establish how much to take.
The other benefit for berberine is that it also helps with cholesterol.
You may want to consider taking alpha lipoic acid along with berberine to prevent the berberine from taking glucose from skeletal muscles.
Berberine has been in use for centuries in China and Middle Eastern countries with no bad side effects.